Volumetric gas analyzers and control devices



W. W. SADLER Filed Feb. 2, 1951 I N V EN TOR. M44 75/? W 510mm I ATTORNEY VOLUMETRIC GAS ANALYZERS AND CONTROL DEVICES April 14, 1953 Patented Apr. 14, 1953 UNI-TED STATES PATENT ()FFICE VOLUMETRIC GAS ANALYZERS AND CONTROL DEVICES invention relates to. ameans and method for controlling the gaseous exchangezot the avian embryo in an. incubator. I

The principal object of the invention is'topro vide adevice which will automatically and accurately replace.gaseousdeficienciesin an incubator atmosphere at regular pro-set intervals;

Another objectof the invention is to provide means which. williautomatically analyze the -at.-- mosphere. at regular intervals and supply any deficiency of desirable gases in direct proportion to the. indicated deficiency.

Other objects and advantagesresideinthe detail construction. of the invention, vvhich" is d'e-' signedior simplicity, economy, and efiiclency. These will. become. more apparent from. the; following description.

In theiollowing detailed description of the in. vention, reference is had to. the; accompanying drawing which forms; a part hereof. Like numorals refer to likezparts in allviews' of thedrawing-..and.throughout the description.

In the drawing:

Fig. I is a diagrammatic viewillustrating the improved method and means for automatically controlling the gas. content of an incubator;

Fig; 2-v is a. diagram of the. electric circuits'employed in the improved system; and

Fig; 3 is anenlarged; vertical section. through aformof control-valve employed in the improved automatic gas' supply system.

IniFig. 1, an incubator is indicated-at I0, and 'a gas"tank iis illustratedat I I The principal gas necessary to control in an incubator is carbon dioxide-although the control of the-oxygen-supply": is also important;

The improved system will" be herein described as supplying carbon dioxide gas to the incubator. The same system, or a duplicate-thereof, could be employed for supplying-oxygen, as will be later described.

The improved system is designed to supply-a gas, such ascarbon dioxide; from the tank It to the-incubator I in a direct proportion to the defi'ciency'of this-gas'in the incubator. This'i's'accomplished by means of three vertically aligned, closedcylinderszan absorbent cylinder I 2, a float cylinder I3, and a water cylinder I4. The cylindersv I3 and I4 are connected together by means of a below-surface connection I5 and are substantially'filled' with water, as indicated at I6. For use'with carbon dioxide; the absorbent cylinderi I2 is filled withssodium hydroxide solution (No.01 to the-level indicated-at H, andthe' cylinder I2 communicates with the cylinder I4 through an above-surface connection I8? 3 Atmosphere-from the incubator I0 is forced into. the bottom of the absorbent cylinder [2 through a supply conduit i9 from a pump 20 which draws air from the incubator I0 through a pumpsupply pipe 2!. The pipe 2| is provided with a check valve 22 to prcventthe return of air to. the incubator "Land the supply conduit I9 is provided witha-similar checkvalve 23 to prevent the-return of air'to the pump 28. A piston 24 is reciprocally mounted. in thepump 28 and isactuated in any desired manner to periodically complete: onecycle: ofv operation.

Asillustrated, the. pump piston 24 is provided with? a piston. rod 25 connected through the medium of a connectingv rod 25 with a crank pin 2.! on a discgear-ZB. The gear is driven from an electric motor 29.

The systemacan be designed to cause the piston 24 to make any desired number of strokes before the current tothe. motor is cut oil. In the system illustrated; theipump 20 isrof a size to furnish the required sample. of air with one complete stroke'oi the piston 24; and. the. motor 29 is automatically stopped: upon completion of the one cycle" of operation.

This is accomplished by the circuits diagrammed in Fig; 2, in which: the operating current'is'supplied-from: supply leads 3!) and3'I The lea'd30 is connected direct to the motor 29. The lead 3I-is connected to a'mctor switch 32 which is closedby means of a cam 33 actuated-from an electric clock 34. A motor conductor 35 1eads from the 'motor switch 32 to the motor 29..

A circuit-holding cam 33 is mountecl' on a shaft 31, upon which the disc gear 23 is mounted, so as to rotate with the latter. A circuit-holding switch 38 is arrangedto be opened by the cam 3Band is bridged across the switch 32 by means of conductors 39.

Thus, it can be seen that at pro-set time in.- tervalsthe cam 33-wii1 close the motor switch 32.- This will'start the motor 29,. causing the holding cam 36 to rotate and the piston to draw air. from theincubator- I0. The clock cam. 33 will now open the switch 32, but the circuit will be held closed by the holding switch 38 which closes when the cam 33 starts to rotate The circuit: will remain closed: until the pump. piston finishes its. cycle, at which time the holding switch 3l8 will be opened by the cam 36.

The sizeof the pump 20 is'designed to displace a predetermined samplev quantity of air. This sample quantity is forced; through the. pipe: I9 to the absorbent cylinder I2, where it bubbles upwardly throughs theisodium hydroxide therein to increase the pressure in the upper portion of the cylinder 12. This pressure is transferred to the water cylinder [4, where it acts to depress the water therein, forcing the latter into the float cylinder [3, thus resulting in a lower water level in the cylinder l4 and a higher water level in the cylinder 13. This variation in water level in the cylinder !3 is employed to raise and lower a float 40, which is slidably mounted in a float chamber 4| mounted on top of the float cylinder l3.

The movements of the float 40 are transmitted by means of a float rod 42 to a gas regulating valve 43. The valve 43 is placed in a carbon dioxide line 44 leading from the carbon dioxide tank H to the incubator ill. The regulating valve 43 is provided with a graduated valve member of any design which will allow gas to flow in direct proportion to the amount of lift of the valve. As illustrated, it comprises an inverted, graduated cone 45 which at its largest diameter completely closes a valve seat 46 and gradually opens the seat, in correspondence to the incline of the cone, as the cone is elevated.

Let us assume that the pump piston 2 makes one complete cycle so as to draw a measured sample of atmosphere from the incubator l into the pump and force the latter sample into the absorbent cylinder I2. The carbon dioxide content in the atmosphere will be absorbed in the sodium hydroxide l7, allowing the remainder of the atmosphere to bubble from the top of the solution. Naturally, the greater the carbon dioxide content of the sample, the less will be the amount of atmosphere bubbling from the top of the sodium hydroxide. Therefore, the amount of air in the top of the cylinders l2 and i l will be in inverse proportion to the carbon dioxide content of the sample.

The pressure created by the residual atmosphere will cause the water in the cylinder l3 to rise so as to lift the float ll) and the valve member 45 in inverse proportion to the carbon dioxide content within the sample. For instance, should there not be any carbon dioxide in the sample, the full cubic contents of the sample will be imposed upon the water in the cylinder 14 so as to raise the water in the cylinder I3 to its maximum point, thus admitting a maximum amount of carbon dioxide to the incubator. Should the sample consist of substantially all carbon dioxide, the latter will be absorbed in the absorbent cylinder I! so that no pressure will be created on the water and the valve member 45 will not open.

Means must be provided for restoring the system to normal after the sample has been analyzed and gas deficiency corrected. This may be accomplished in many ways, either mechanically or electrically. As illustrated, an exhaust pipe 41 is placed at the top of the cylinder I2 and controlled by a solenoid valve 68. The solenoid of the valve 48 is connected to the supply lead 30 by a conductor 49, and to the lead 31 through a second conductor 50 in series with which a valve switch Si is placed. The switch i is positioned to be closed by the cam 36, or by a separate cam on the same cam shaft, slightly in advance of the opening of the witch 38.

Therefore, it can be seen that at the completion of the sampling, the solenoid valve will be opened to allow the air under pressure of the water head in the float cylinder to escape so as to lower the float and close the valve member 45 to await the next impulse from the clock 34.

While the system has been described as relating to carbon dioxide, it could be used on any other gas capable of being absorbed in a liquid absorbent in the absorbent cylinder 12. For instance, should it be desired to control the oxygen content in the incubator as well as the carbon dioxide, the cylinders l2, l3, and i4 would be repeated to control a second valve 33 in an oxygen line feeding the incubator. The second absorbent cylinder would contain pyrogallic acid for absorbing the oxygen from the sample received from the pump 26.

' Should it be desired to delay the opening of the exhaust valve for a period after the stopping of the motor, it would be within the skill of any electrician to place a delayed relay in series with the conductor 49 or 50 to control the current supply to the solenoid valve.

Funnels 52 and filling valves 53 are provided for filling the cylinders l2, l3, and i4, and drain cocks 54 are provided for draining these cylinders so that the desired fluid levels may be attained therein.

While a specific form of the improvement has been described and illustrated herein, it is to beunderstood that the same may be varied, within the scope of the appended claim, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is: An apparatus for controlling the supply of a predetermined gas to an incubator comprising: a pump having an inlet pipe connected with the incubator; a check valve in said inlet pipe preventing flow from said pump; a vertically disposed absorbent tank adapted to contain a liquid absorbent for the said gas; a pressure condult connecting said pump to the lower portion of said absorbent tank; a check valve in said pressure conduit preventing return flow to said pump; a pair of water cylinders disposed vertically adjacent said absorbent tank and interconnected adjacent their lower ends and adapted to contain water; an unobstructed connecting pipe communicating between the upper portion of said absorbent tank and the upper portion of the first of said pair of cylinders; a verticallydisposed, open-ended float chamber extending upwardly from the top of the second of said pair of cylinders; a float movable vertically in said second cylinder and extending upwardly therefrom into said float chamber; a stem extending upwardly from said float through the float chamber and outwardly through the upper end thereof; a storage tank for gas; a gas pipe connecting the storage tank to the incubator; a valve in said gas pipe, which valve includes a casing having a horizontal partition formed with an opening, and a closure for the opening shiftable vertically to opened and closed positions; and a stem extending from said closure through the bottom of said casing and being connected with the stem of said float whereby the closureis shifted to the opened and closed positions in response to the vertical movements of the float.

WALTER W. SADLER.

References Cited in'the flle of this patent UNITED STATES PATENTS Number Name Date 813,671 Schlatter et al. Feb. 27, 1906 1,435,846 I-Iogg Nov. 14, 1922 2,056,663 Foulke Oct. 6, 1936 2,299,109 Rand Oct. 20, 1942 

